OD on or off?? 08 V8 6sp

[JDC81]

Ok guys I have a question for you. I have always been told to tow with OD off, but I was going through my Explorers manual and it says nothing about turning it off. I have a 08 4.6l V8 with the 6speed and tow package. So here is the deal, I just bought a 3500lb starcraft travel trailer and on the way home (1hr drive) i tried it both ways. with OD off it seems to go into 4th and stay there. With OD on it would stay in 6th but go into 5th on hills, almost never going down to 4th. So if it never goes into 4th with OD on, do I just let it figure out what gear it needs to be in? Thanks.

 

[thebrakeman]

Most conservative way is to never tow with OD enabled. In my opinion, this is very old school logic which dates back to when vehicles had no monitoring equipment to protect itself.

Next most conservative would be to follow what the owners manual says. For a long time, some vehicles said it was OK, others said to stay out of it when towing.

IMO, the most realistic method is to simply pay attention to what the tachometer is doing, and act accordingly. This is what a lot of vehicles manuals call for now...if it's shifting a lot, due to hills, wind, and/or use of cruise control, take it out of OD until conditions change. Otherewise OD is fine.

When I towed our camper home (roughly 4000 lbs empty), it would hold 5th gear (OD enabled), and the convertor seemed to be locked. I'm hoping that will be the case even when loaded, so I don't have to tow in 4th (OD button).

I recently purchased a ScangageII so I can monitor trans fluid temp, gear ratio, torque-convertor slip, and other variables, so I will know what's really going on.

 

[thebrakeman]

PS,
To answer your last questions, I think you are fine letting the trans figure out what to do (leave the OD on), as long as you are sure the torque convertor is not running unlocked all the time. If you are running 5th gear with the convertor unlocked, you will be builidng heat in the fluid. Running 4th gear with convertor locked would give you the same or better gas mileage, and reduce fluid temps.

The problem is if the truck was wanting to run 6th gear with the convertor unlocked. But I don't think it would ever do that. 5th and 6th are both OD gears, and I think it's smart enough to never run 6th-unlocked for any extended period.

But again, I would want to be absolutely sure (hence the Scanguage).

 

[JDC81]

Sounds good, that what I was thinking, but I just wanted to be sure. Always good to get others opinions, especially since i havent towed much. Thanks again!

 

[v8merc]

Where I live in western PA, I leave it out of o/d. Way too many hills. I have always been told that excessive shifting is what cause heat and heat causes trans. failure. My thoughts are this: at 60 mph I am taching about 26 to 2700 rpm. I can live with that. Truck feels strong and pulls my travel trailer (5500lbs) like a champ.

 

[donstevens]

I have an 06 XLT V8 two wheel drive with towing package. I tow a 1500 lb open car trailer with 2500 lb car and gear. It tows well. I figure I am adding 4500 lbs when towing. If I read the manual correctly the vehicle sould have 7300 lb towing capacity. No problems right?

I am here scanning towing an transmission threads to try to answer questions as I fear that I have damaged my trans.

Is towing with OD engaged OK? I agree with JDC81 that the manual says OK. Ford service tech says no.

After a nerve wracking evening of towing (with OD on) I had the dealer change the trans fluid. The service tech at the dealer said "oh no don't tow with OD. The OD bands can't take the lugging". Lugging? I am cruising down level highway at 2000 rpm. I would not define that as lugging.

I don't have a temp guage but have not experienced excessive heat. There is no smell, the trans cooler lines are hot to the touch but not blazing, the old fluid that came out (after slippage and clunking issues) was still red (black cherry vs. new cherry) and did not smell burnt.

I have towed (4500 lbs) with OD on and now have issues that I believe are trans issues. I fear that I may have damaged something the 5th , 6th gear area. What it is I don't know and so far have not found anyone who can explain it to me. No check engine light - No OD light flashing - just clunky when in OD even without load. Tows fine with OD off.

I'd say leave it off - Mileage sucks but gas is a lot cheaper than a tranny rebuild.

If anyone who is the "OD off" persuasion can explain what happens in the tranny and what OD failure symptoms are, I'd really appreciate it.

Don Stevens

 

[v8merc]

These ohc ford v8's were meant to rev. I dont see where the engine taching a little higher when towing is a bad thing other than more fuel usage. My buddy, who is a Ford parts manager and drag racer, says to me to "let it eat". So thats what I do. The only time I will turn the o/d back on is if I see a long straight flat sttrech of road ahead. Where I live, thats not too often.

A far as possible damage to your 5th and 6th gear, I suppose it is possible. Probably caused by too much heat and excessive shifting from one gear to another. The only way to know is to tear it down.